CN101458236A - Method for detecting polycyclic aromatic hydrocarbon in plastic product - Google Patents

Abstract

The invention provides a method for detecting polycyclic aromatic hydrocarbon in a plastic product. The method comprises the following steps: (1) extraction: a plastic product sample is crushed, weighed, wrapped in filter paper, placed in a sample bottle, added with 20mL of a main extractant and an auxiliary extractant which are acetone to dichloromethane and the volume ratio of which is 1:1, and ultrasonically extracted for 60-80min; (2) purification: in a chromatographic column, florisil is adopted to absorb the polycyclic aromatic hydrocarbon in extraction liquid; then the extraction liquid is eluted and collected, and then the obtained eluent is condensed and diluted to the volume; and (3) sample determination: the sample is determined by a gas chromatography, and polycyclic aromatic hydrocarbon components are subject to qualitative analysis and quantitative analysis. In the method, the acetone and the dichloromethane are taken as solvents in the preliminary treatment process of the sample to extract the polycyclic aromatic hydrocarbon from the sample, which greatly shortens the extraction time and improves the extraction efficiency; and the florisil is adopted to purify the extraction liquid, which reduces the interference in the determination of the polycyclic aromatic hydrocarbon in the sample by the gas chromatography with a low detection limit, and the method can meet the requirements for rapidly detecting PAHs in plastic products.

Description

A kind of method that detects palycyclic aromatic in the plastic products

Technical field

The present invention relates to the detection method of palycyclic aromatic in the plastic products, belong to technical field of analysis and detection.

Background technology

Plastic food packing is subjected to the welcome and the great kindness of packaging for foodstuff industry deeply with characteristics such as its light weight, attractive in appearance, practicalities, and its raw material commonly used has Polyvinylchloride (PVC), polyester (PET), polycarbonate (PC), tygon (PE), polypropylene (PP) etc.But along with rapid development of economy, the energy and raw-material supply can not have been satisfied the demand of production, and people turn to sight the development and utilization of regenerative raw materials one after another.The application of the regenerated plastics that occurred on the international market in packaging for foodstuff is used for the production again of beverage packaging as reclaiming the PET bottle, is to be the application that regroups again behind the monomer with the PET depolymerization.China also extensively utilizes regenerated plastics, and calendar year 2001 is 2,230,000 tons of import waste plastics once, wound import tidemark, but have wretched insufficiency aspect the supervision of regenerated plastics utilization.

That palycyclic aromatic (PAHs) is that a class has is carcinogenic, teratogenesis and cause the persistence organic pollutant of gene mutation.The method that existing state mark system detects palycyclic aromatic (PAHs) is by experimental techniques such as evaporation residue, potassium permanganate consumption and mimic solvent stripping quantities, supervises the interpolation of reclaiming waste material and uses.Yet, because it is extremely complicated to reclaim the raw material sources of plastics, contain different types of plastic fraction inevitably, or contain poisonous and hazardous materials such as PAHs, and in the machine-shaping process complicated chemical reaction may take place, make above-mentioned detection method can't detect the harmful organic substance of contaminated food products, harm humans health more exactly.

At present, the method for detection palycyclic aromatic (PAHs) mainly contains: column chromatography and thin-layered chromatography, vapor-phase chromatography (GC), high performance liquid chromatography and mass spectroscopy etc.Column chromatography and thin-layered chromatography have certain separating effect, but can't carry out accurate qualitative and quantitative analysis; Vapor-phase chromatography (GC) and high performance liquid chromatography and mass spectroscopy can be carried out qualitative and quantitative analysis simultaneously, but very high to sample requirement, need anticipate, and remove a large amount of impurity.Because the plastic products compact structure needs tens hours usually, even for more time objectionable impurities is extracted the requirement that could satisfy analyzing and testing.For this reason, set up quick, easy, detection technique seems particularly important cheaply.

Summary of the invention

At the prior art above shortcomings, the purpose of this invention is to provide a kind of quick, easy, detect the method for palycyclic aromatic in the plastic products cheaply.

The object of the present invention is achieved like this: a kind of method that detects palycyclic aromatic in the plastic products comprises the steps:

1). extract: the plastic products sample is crushed to 1～2mm size, takes by weighing about 2g, be accurate to 0.001g, be wrapped in the filter paper, insert in the sample bottle, add acetone and the methylene chloride major-minor extractant 20mL of 1:1 by volume, after carrying out ultrasonic Extraction 40～60min, pour out and slightly get extract; Then, in this sample bottle, add described extractant 20mL again and continue to extract 15min, obtain essence and get extract; Described thick extract and smart extract are merged, and mixing;

2). purify: in the chromatographic column of 1.5cm * 30cm, the Fo Luoli zeyssatite of packing into splashes into the palycyclic aromatic that makes in the chromatographic column in the extract with the extract of above-mentioned merging and is absorbed by Fo Luoli zeyssatite; Then, be the mixed liquor elution chromatography post of methylene chloride and normal hexane successively with 5mL normal hexane, 10mL volume ratio 1:1, collect eluent; After again the eluent of collecting being concentrated, adopt normal hexane to be settled to 5mL;

3). sample determination: adopt vapor-phase chromatography that palycyclic aromatic is measured:

The A.GC condition

Chromatographic column: DB-5 capillary column;

Heating schedule: 60 ℃ keep 1min, rise to 210 ℃ with 10 ℃/min, rise to 260 ℃ with 3 ℃/min again, at last with 290 ℃ of 5 ℃/min, keep 5min;

Carrier gas N ₂, flow velocity is 30ml/min

250 ℃ of injector temperatures;

300 ℃ of fid detector temperature;

Sample size 1 μ L, split ratio 1: 2;

B. measure: under identical chromatographic condition, advance the sample extracting solution and the palycyclic aromatic standard solution of equal volume respectively, measure the retention time and the chromatographic peak area of each component, carry out the qualitative and quantitative analysis.

Compared to existing technology, the present invention has following beneficial effect:

(1) the present invention is in the process of sample pre-treatments, adopted major-minor solvent that palycyclic aromatic in the sample (PAHs) is extracted, shortened extraction time greatly, improved extraction efficiency, adopt Fo Luoli zeyssatite that extract is purified, reduced the interference when other material is to gas Chromatographic Determination PAHs in the sample, and detection limit of the present invention is low, can satisfy the needs of PAHs in the fast detecting plastic products.

(2) the present invention adopts main extractant to cooperate a kind of macromolecule sweller as the auxiliary extraction agent, make the secondary structure of destroying high molecular polymer after the plastic products swelling, thereby open the passage of target substance in more extraction samples, palycyclic aromatic is extracted in the extractant from plastic products apace, thereby set up the method for palycyclic aromatic (PAHs) in a kind of fast detecting plastic products.

(3) the inventive method can be removed other organism to the interference that palycyclic aromatic (PAHs) detects, and is applicable to that metering quality testing department measures the palycyclic aromatic in the plastic products easily and quickly, has advantages such as analyst coverage is wide, efficient is high, cost is lower.

Description of drawings

Fig. 1 is the GC-FID spectrogram of sample extracting solution;

Fig. 2 is the GC-FID spectrogram of PAHs standard solution.

Embodiment

A kind of method that detects palycyclic aromatic in the plastic products, step is as follows:

1. extract: the plastic products sample is crushed to 1～2mm, takes by weighing about 2g, be accurate to 0.001g, be wrapped in the filter paper, insert in the sample bottle, add major-minor extractant (acetone and methylene chloride be the mixed solution of 1:1 by volume) 20mL, behind the ultrasonic Extraction 60min, pour out and slightly get extract; Then, add this kind extractant 20mL again and continue to extract 15min, obtain essence and get extract; Described thick extract and smart extract merge, mixing.

2. purify: in the chromatographic column of 1.5cm * 30cm, the Fo Luoli zeyssatite of packing into splashes into the palycyclic aromatic that makes in the chromatographic column in the extract with the extract of above-mentioned merging and is absorbed by Fo Luoli zeyssatite; Then, use mixed liquor (volume ratio 1:1) the elution chromatography post of 5mL normal hexane, 10mL methylene chloride and normal hexane successively, collect eluent; After again the eluent of collecting being concentrated, adopt normal hexane to be settled to 5mL.

3. sample determination: adopt vapor-phase chromatography (GC) that palycyclic aromatic is measured.

The A.GC condition

Heating schedule: 60 ℃ keep 1min, rise to 210 ℃ with 10 ℃/min, rise to 260 ℃ with 3 ℃/min again, with 5 ℃/min290 ℃, keep 5min at last;

Chromatographic column: DB-5 capillary column;

Carrier gas N ₂, flow velocity is 30ml/min;

250 ℃ of injector temperatures;

300 ℃ of fid detector temperature;

Sample size 1 μ L, split ratio 1: 2;

B. measure: under identical chromatographic condition, advance sample extracting solution and the palycyclic aromatic standard solution of equal volume (1 μ L) respectively, measure the retention time and the chromatographic peak area of each component, carry out the qualitative and quantitative analysis.

By sample 1 is carried out actual detected, obtain the GC-FID spectrogram of sample extracting solution shown in Figure 1; Simultaneously, the palycyclic aromatic standard solution is carried out stratographic analysis under identical chromatographic condition, obtain the GC-FID spectrogram of palycyclic aromatic standard items extract shown in Figure 2.Qualitative by retention time, the peak area normalization method is quantitative.Try to achieve the content of each component in sample according to the concentration of each component standard solution of palycyclic aromatic (PAHs) and the typical curve of respective peaks area linear fit, as shown in table 1.These computing method do not repeat at this for existing mature technology.

The measurement result of PAHs in certain plastic products of table 1

The inventive method can be removed other organic substances to the interference that polycyclic aromatic hydrocarbon (PAHs) detects, and is applicable to the inspection of metering quality Survey department measures the polycyclic aromatic hydrocarbon in the plastic products easily and quickly, has that analyst coverage is wide, efficient is high, cost is lower etc. Advantage.

Claims (1)

1, a kind of method that detects palycyclic aromatic in the plastic products comprises the steps:

1). extract: the plastic products sample is crushed to 1～2mm size, takes by weighing about 2g, be accurate to 0.001g, be wrapped in the filter paper, insert in the sample bottle, add acetone and 1: 1 by volume major-minor extractant 20mL of methylene chloride, after carrying out ultrasonic Extraction 40～60min, pour out and slightly get extract; Then, in this sample bottle, add this kind extractant 20mL again and continue to extract 15min, obtain essence and get extract; Described thick extract and smart extract are merged;

2). purify: in the chromatographic column of 1.5cm * 30cm, the Fo Luoli zeyssatite of packing into splashes into the palycyclic aromatic that makes in the chromatographic column in the extract with the extract of above-mentioned merging and is absorbed by Fo Luoli zeyssatite; Then, use the 5mL normal hexane successively, and the 10mL volume ratio is the mixed liquor elution chromatography post of methylene chloride and normal hexane at 1: 1, collects eluent; After again the eluent of collecting being concentrated, adopt normal hexane to be settled to 5mL;

3) sample determination: adopt vapor-phase chromatography that palycyclic aromatic is measured:

The A.GC condition

Chromatographic column: DB-5 capillary column;

Heating schedule: 60 ℃ keep 1min, rise to 210 ℃ with 10 ℃/min, rise to 260 ℃ with 3 ℃/min again, at last with 290 ℃ of 5 ℃/min, keep 5min;

Carrier gas N2, flow velocity are 30mL/min;

250 ℃ of injector temperatures;

300 ℃ of fid detector temperature;

Sample size 1 μ L, split ratio 1: 2;

B. measure: under identical chromatographic condition, advance the sample extracting solution and the palycyclic aromatic standard solution of equal volume respectively, measure the retention time and the chromatographic peak area of each component, carry out the qualitative and quantitative analysis.

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